1
Department of Multimedia Systems
M
ULTIMEDIAT
ECHNOLOGIESExercise No. 7:
METHODS
OF
CREATING
STEREOSCOPE
IMAGES
Authors:
Bartosz Kunka
Piotr Odya
1. Tasks
This laboratory exercise consists of three parts. In the first part, students implement in the Matlab environment three algorithms used for creating stereoscopic images These algorithms should be implemented as Matlab scripts (.m). In this way, students recognize technical aspects of stereoscopic image creation from two 2D images.
The task for students is to implement in Matlab three anaglyph image equations and an algorithm for creating the image used in the polarization technique.
The created images should be named as following: • 1_color
• 2_half-color • 3_Dubois • 4_polar
All the received stereoscopic images should be presented to the teacher before the end of the classes. Color anaglyph ⋅ + ⋅ = B G R B G R B G R R R R L L L A A A 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1
Half color anaglyph
⋅ + ⋅ = B G R B G R B G R R R R L L L A A A 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 114 , 0 587 , 0 299 , 0 Dubois anaglyph ⋅ − − − − − − + ⋅ − − − − − − = B G R B G R B G R R R R L L L A A A 2264 , 1 112961 , 0 0721527 , 0 0184503 , 0 73364 , 0 378476 , 0 00155529 , 0 0879388 , 0 0434706 , 0 00546856 , 0 0205971 , 0 0152161 , 0 0157689 , 0 0378246 , 0 0400822 , 0 176381 , 0 500484 , 0 4561 , 0 Another form: AR = 0.4561⋅LR + 0.500484⋅LG + 0.176381⋅LB – 0.0434706⋅RR – 0.0879388⋅RG – 0.00155529⋅RB AG = – 0.0400822⋅LR– 0.0378246⋅LG – 0.0157589⋅LB + 0.378476⋅RR + 0.73364⋅RG – 0.0184503⋅RB AB = – 0.0152161⋅LR – 0.0205971⋅LG – 0.00546856⋅LB – 0.0721527⋅RR – 0.112961⋅RG + 1.2264⋅RB
2 Important:
1) Color images are represented in Matlab as three two-dimensional matrix, each of the matrices consist of one color component: R, G and B.
Lr = L(:,:,1); Image Lr is the R component of the L (left)
image
A(:,:,2) = L(:,:,2); Green component of the anaglyph image is equal to Green component of the L image
2) A matrix should initially fulfilled with zeroes
Lr = zeros(size(L), 'uint8');
where size (L) is the size of the source image
In the second part of the classes, students will get acquainted with a free application used to create images: 3D StereoPhoto Maker. Students are asked to assess how changing parameters (including the spread of the left and right components) affects the quality of the perceived 3D effect - both in anaglyphic and polarizing techniques.
For the files specified by the teacher, students must find the optimal spacing of the left and right image components (using arrows keys). They should evaluate the quality of the obtained 3D image and the perceived spatial effect for the four algorithms: color (red / cyan), half-color, Dubois and Interlaced.
In the third part, students use StereoMovie Maker application to create stereoscopic videos. The students should use the files specified by the teacher. The tasks are like these for the static images.
2. References
E.M. Mouaddib, Stereovision with a Single Camera and Multiple Mirrors, IEEE Int. Conf. Robotics and Automation, ICRA’2005, 800-805, 2005.
M. Inaba, A stereo viewer based on a single camera with view-control mechanisms, IEEE International Conference on Intelligent Robots and Systems, vol. 3, 1857- 1865, 1993. NARKHEDE S., GOLSHANI F., Stereoscopic imaging: a real-time, in depth look, IEEE Potentials,
vol. 23, issue 1, 38-42, 2004.
O. Schreer, 3D Videocommunication, Wiley 2005.
http://ccrs.nrcan.gc.ca/resource/tutor/stereo/chap3/chapter3_4_e.php http://en.wikipedia.org/wiki/Anaglyph_image#Depth_adjustment
3 Applications and images are located in D:\Technologie multimedialne\!cw07
1. Describe differences in the perception of the 3D effect by comparing the algorithms of
creating anaglyphic images
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2. What are the advantages and disadvantages of the anaglyph method? What about the
polarizing methods? Which allows for better image quality?
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3. How moving the image components (in the horizontal plane) affects the stereoscopic
image? ………... ………... ………... ………... ………...
MULTIMEDIA TECHNOLOGIES LABORATORY
No. 7
METHODS OF CREATING STEREOSCOPE IMAGES
Students: Mark:
Group:
4
4. How moving the image components (in the vertical plane) affects the stereoscopic
image?
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5. What should be done to obtain the effect of "coming out of the screen”? Which method
gives the best results? Why?
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6. Do changes in the head position (left-right, closer-further) affect the quality of the 3D
image? Why?
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7. For which scenes the 3D effect is most easily seen?
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8. Observations, conclusions and comments
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